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Biomedical subjects

G Moschini

Publications and source records attributed to G Moschini.

At least 37 records · Page 2Linked to original sources
PubMed1993

Plasma selenium and glutathione peroxidase activities in individuals living in the Veneto region of Italy.

In order to assess the Se status in individuals living in the Veneto region, a series of related measurements was performed. These included plasma selenium by PIXE and glutathione-peroxidase (GSH-Px) activities in plasma, red blood cells and platelets. Individuals were either normals or people suffering from various liver diseases. Moreover, an oral supplement of sodium selenite was given to 13 patients suffering from stable chronic renal failure (CRF) in parallel to 26 normals: data on plasma GSH-Px and on serum creatinine and creatinine clearance were collected either before or after supplementation. Results were in support of a relatively low selenium status: mean +/- SD plasma Se values of normals (0.82 +/- 0.17mumol/L, n = 82) were comparable to data observed in European regions where Se deficiency was already known. Even lower values were observed in those with liver diseases. Among enzyme activities, the distribution of the data of platelet GSH-Px was in further support of low Se status in the evaluated individuals. After Se supplementation, both normals and CRF patients showed a significant increase in the creatinine clearance, reflecting an improvement of the glomerular filtration rate. We suggest that more extensive surveys of the Se status should be carried out in Italy; moreover, Se supplementation may be advisable in individuals affected with moderate impairment of renal function.

Administration, Oral↗
PubMed1993

[The role of infective intestinal complications on the course of Crohn's disease and ulcerative rectocolitis].

The authors studied the incidence of protozoal and bacterial infection in 41 cases of Crohn disease und ulcerative colitis; the effect of anti infective therapy on the clinical course has also been tested. Patients with ulcerative colitis are more frequently involved in this type of complication than those with Crohn disease. Therapy has a positive influence on the course of the disease; therefore systematic study of the faeces for bacteria and parasites is necessary for a correct understanding of chronic inflammatory bowel disease and for specific treatment.

Adolescent↗
PubMed1992

Selenium and glutathione peroxidase variations induced by polyunsaturated fatty acids oral supplementation in humans.

Serum and erythrocyte selenium, erythrocyte and platelet glutathione-peroxidase (GSH-Px) activities, and erythrocyte reduced glutathione (GSH) content were measured in 25 healthy adult individuals before and after daily supplementation with 20 ml of fish oil for 10 weeks. Serum-Se decreased from 0.83 +/- 0.01 mumol/l to 0.75 +/- 0.02 mumol/l (mean +/- S.E.M.) (P less than 0.01); erythrocyte-Se decreased from 4.39 +/- 0.17 nmol/g hemoglobin (Hb) to 2.83 +/- 0.15 nmol/g (P less than 0.001). GSH-Px activities increased both in erythrocytes (6.93 +/- 0.24 iu/g vs 8.18 +/- 0.27 iu/g Hb, P less than 0.01) and in platelets (69.2 +/- 2.8 iu/g vs 90.9 +/- 3.6 iu/g protein, P less than 0.001). The concentration of GSH in erythrocytes fell from 9.56 +/- 0.29 mumol/g Hb to 5.90 +/- 0.30 mumol/g Hb (P less than 0.001). The effects on plasma lipids were evident only for triglycerides (before 1.96 +/- 0.16 mmol/l, after 1.75 +/- 0.14 mmol/l, P less than 0.001). We hypothesise the enrichment of erythrocyte and platelet membranes with polyunsaturated fatty acids (PUFAs), following fish oil intake, can generate increased amounts of lipid peroxides and thus allosterically activate GSH-Px: with time this is harmful for the integrity of the enzyme molecule and Se release may result. We suggest that the Se status of individuals given PUFAs is assessed before and during intake; Se supplements should only be given when serum and/or erythrocyte Se are reduced.

Administration, Oral↗
PubMed1992

Erythrocyte antioxidant activity, serum ceruloplasmin, and trace element levels in subjects with alcoholic liver disease.

Erythrocyte antioxidant enzymes (superoxide dismutase, catalase, glutathione peroxidase) and reduced glutathione, serum ceruloplasmin, and serum trace elements (copper, zinc, iron, and selenium) related to antioxidant enzymes were assayed in subjects with alcoholic liver disease of different degrees of severity. The erythrocytes of subjects with moderate and severe alcoholic liver cirrhosis had an unbalanced antioxidant system (normal superoxide dismutase, low catalase and glutathione peroxidase activities, and low glutathione content). Serum ceruloplasmin levels were in the normal range. Levels of the serum trace elements zinc and selenium were significantly low in subjects with moderate and severe cirrhosis, whose red cell half-life was also significantly short, as measured by radioactive chromium. These data suggest that the erythrocytes of subjects with moderate and severe alcoholic liver cirrhosis are less protected against oxidant stress. The particular erythrocyte antioxidant system and serum trace element pattern may play a role in the genesis of hemolytic disorders and of alcoholic hepatic damage.

Adult↗
PubMed1991

Mutation induction and RBE-LET relationship of low-energy protons in V79 cells.

The mutation induction at the HGPRT locus has been studied in V79-753B Chinese hamster cells irradiated with proton beams with energies of 3.36, 1.70 and 1.16 MeV, corresponding to average LET values of 10.6, 17.8 and 23.9 keV/microns, respectively. The mutation curve obtained with 200 kV X-rays was used for comparison. The mutation frequency induced by all the proton beams is considerably higher than that induced at the same dose by X-rays and it is linearly related to the dose. Moreover, the proton effectiveness increases with the LET. The RBEs (evaluated as the initial slope ratios) are 5.0 +/- 0.8, 5.4 +/- 0.8 and 7.7 +/- 1.2 for protons with average LETs of 10.6, 17.8 and 23.9 keV/microns, respectively. These values are higher than those reported in the literature for other ions of comparable LET. This finding parallels what we have already found for cell inactivation (for which RBEs of 3.0, 4.6 and 7.3 were obtained at the same LETs), and indicates that for mutation induction, also, the RBE-LET relationship may depend on the type of radiation.

Animals↗
PubMed1990

Selenium supplementation increases renal glomerular filtration rate.

Selenium (Se) is a trace element variously distributed in the human body and especially concentrated in certain organs, such as the renal cortex. We report results obtained during a ten weeks' oral Se supplementation. Experiments were devised to evaluate previous preliminary observations which suggested a possible effect of Se addition on the renal glomerular filtration rate. Eleven healthy volunteers have given increasing oral Se (as a sodium selenite solution) as follows: on the first week they have given 100 micrograms Se per day; this was progressively increased 100 micrograms per day for each of the following 6 weeks; the last dose (700 micrograms per day) was maintained for three further weeks. Serum and 24-hour urine were collected weekly for creatinine determination by kinetic Jaffé reaction and Se measurement by proton-induced X ray emission (PIXE). The final mean serum creatinine concentration was 13% lower than the initial mean value (p less than 0.01). Mean creatinine clearance increased significantly (p less than 0.05) and showed a direct correlation with mean Se clearance (r = 0.79; p less than 0.001). As the increase of creatinine clearance was concomitant with a reduction of serum creatinine levels, we excluded the possibility of toxic effects. Our results seem to suggest a positive influence of Se supplementation on the rate of glomerular filtration and we hypothesize that Se might be involved in the vascular regulatory mechanism of the kidney.

Adult↗
PubMed1989

Serum selenium in liver cirrhosis: correlation with markers of fibrosis.

In 55 patients with alcoholic cirrhosis and in 47 healthy individuals we assayed the concentration of selenium in serum (S-Se) by proton induced X-ray emission, the aminoterminal peptide of type III procollagen (NPIIIP) by RIA and the plasma fibronectin (FN) by immuno-nephelometry, together with routine biochemical tests. S-Se was lower in cirrhosis than in controls (0.57, SD 0.20 vs 0.92, SD 0.16 mumol/l; p less than 0.001) and was more reduced in ascitic than in compensated patients (0.50, SD 0.19 vs 0.66, SD 0.17 mumol/l; p less than 0.001). Regression analysis showed a positive correlation of S-Se with serum albumin and FN, whereas necrotic or inflammatory activity seems unrelated to S-Se; a negative correlation was found between S-Se and NPIIIP, suggesting a protective role of selenium against fibrosis.

Adult↗
PubMed1989

RBE-LET relationship for the survival of V79 cells irradiated with low energy protons.

The survival of V79 Chinese hamster cells irradiated with proton beams with energies of 0.73, 0.84, 1.16, 1.70 and 3.36 MeV, corresponding to LET values, evaluated at the cell midplane, of 34.5, 30.4, 23.9, 17.8 and 10.6 keV/micron respectively, have been studied in the dose range 0.5-6.0 Gy. As a reference, the survival curve obtained with 200 kV X-rays was used. The initial shoulder, typical of survival curves obtained with sparsely ionizing radiation, decreases as the LET increases and completely disappears at 23.9 keV/micron. This value corresponds to the maximum of the RBE, expressed as the initial slope ratio. In the energy range we have considered, the RBEs for protons are higher than those reported for other ions of comparable LET and the RBE-LET relationship results shifted to lower LET values. Our data seem to indicate that the RBE-LET curve depends on the type of radiation and this could imply that LET is not a good reference for the dose-effectiveness relationship.

Animals↗
PubMed1989

DNA repair after gamma irradiation in lymphocytes exposed to low-frequency pulsed electromagnetic fields.

The effect of exposure to extremely low-frequency pulsed electromagnetic fields (EMFs) on DNA repair capability and on cell survival in human lymphocytes damaged in vitro with gamma rays was studied by two different micromethods. In the first assay, which measures DNA repair synthesis (unscheduled DNA synthesis, UDS), lymphocyte cultures were stimulated with phytohemagglutinin (PHA) for 66 h and then treated with hydroxyurea (which blocks DNA replication), irradiated with 100 Gy of 60Co, pulsed with [3H]thymidine ([3H]TdR), and then exposed to pulsed EMFs for 6 h (the period in which cells repaired DNA damage). In the second assay, which measures cell survival after radiation or chemical damage, lymphocytes were first irradiated with graded doses of gamma rays or treated with diverse antiproliferative agents, and then stimulated with PHA, cultured for 72 h, and pulsed with [3H]TdR for the last 6 h of culture. In this case, immediately after the damage induced by either the radiation or chemicals, cultures were exposed to pulsed EMFs for 72 h, during which cell proliferation took place. Exposure to pulsed EMFs did not affect either UDS or cell survival, suggesting that this type of nonionizing radiation--to which humans may be exposed in the environment, and which is used for both diagnostic and therapeutic purposes--does not affect DNA repair mechanisms.

Adolescent↗
PubMed1987

Antioxidant system and serum trace elements in alpha-thalassaemia and Hb Lepore trait.

Erythrocyte antioxidant enzymes, superoxide dismutase, catalase and glutathione peroxidase were found to be significantly high in subjects with alpha-thalassaemia and Hb Lepore trait, as a consequence of the increased oxidant stress which is known to exist in these conditions. Among the serum trace elements present in these enzymes, selenium was increased in subjects with Hb Lepore trait and significantly low in those with alpha-thalassaemia trait, while selenium erythrocyte content was significantly increased in alpha-thalassaemic subjects.

Adult↗
PubMed1983

Erythrocyte antioxidant enzymes and selenium serum levels in an Andean population.

A preliminary study indicated that erythrocyte antioxidant enzyme activities were enhanced in chronic hypoxaemic patients, in whom an increased oxidant stress could be present as a consequence of augmented haemoglobin autoxidation. We have now evaluated the behaviour of erythrocyte antioxidant enzymes and of their related trace metal serum levels in conditions of chronic hypobaric hypoxia in an Andean population living at high altitude (3800 m above sea level), and in a similar ethnic group living at sea level. The results indicate a significant reduction in erythrocyte glutathione peroxidase activity and a low serum level of selenium in the Andean population. Thus, in contrast to what happens in chronic hypoxaemic patients, this group of Andean subjects seems to be poorly protected against oxidant stress, probably as a consequence of selenium deficiency in the diet.

Adult↗
PubMed1980

Serum selenium levels in malignant lymphoproliferative diseases.

Serum selenium levels were measured in 38 patients with malignant lymphoproliferative diseases (MLD) and in 34 non-hospitalized healthy individuals. Selenium was determined by proton induced x-ray emission. In Hodgkin's disease and non-Hodgkin malignant lymphoma the mean serum levels of selenium were not different from those of the control group. On the contrary lowered mean serum selenium concentrations were observed in the group with chronic lymphocytic leukaemia (5.2 +/- 0.7 microgram/100 ml) as compared to normal individuals (7.9 +/- 0.3 microgram/100 ml). The difference is highly significant (P less than 0.005). A second selenium test was made in 11 out of the 38 patients within 8 weeks from the beginning of radiotherapy or chemotherapy; unchanged levels were found.

Adolescent↗
PubMed1979

Neonatal erythrocyte glutathione peroxidase deficiency as a consequence of selenium imbalance during pregnancy.

The red blood cell (RBC) glutathione peroxidase (GSH-Px) activity and routine haematological parameters were measured in 38 healthy north Italian full-term pregnant women and in their newborn infants. In 31 pairs the serum selenium concentration was also measured. Data were compared with those of 20 normal adult controls (10 males and 10 females). Newborn infants exhibited significantly lower RBC GSH-Px activity and serum selenium concentrations than adult controls. Pregnant women had serum selenium values intermediate between those of adult female controls and their newborn infants. In both the pregnant women and newborns the RBC GSH-Px activity correlated with the level of selenium in serum which suggests that the neonatal RBC GSH-Px deficiency may be partially due to insufficient availability of selenium during pregancy. Factors other than selenium concentration, e.g. hormonal and genetic, might also affect the RBC GSH-Px activity as suggested by sex differences and mother/child concordances in enzyme activity found in our cases.

Adolescent↗
PubMed1977

Erythrocytic glutathione peroxidase: its relationship to plasma selenium in man.

Erythrocytic glutathione-peroxidase (GSH-Px) activity and plasma selenium concentrations were measured in 14 patients: 7 with iron deficiency and 7 with raised serum iron levels. The decreased enzymatic activity in iron deficiency was confirmed. Plasma selenium was significantly lower in patients with lower serum iron; furthermore there is a significant correlation between serum iron and plasma selenium concentrations. Another correlation even more significant was found between plasma selenium and enzyme activity in all the cases we studied. These data suggests that the importance of iron for GSH-Px activity may be merely due to its relationship with selenium and that plasma selenium concentration may be of critical importance for enzyme activity.

Anemia, Hypochromic↗